Tubular actuating mechanisms or devices for reeling and unreeling of roll-type closures are known in the art to provide a compact and convenient means for mechanically driving such closures. The tubular form allows to arrange these mechanisms e.g. inside of the roller of the roll-type closures, whereby a particularly compact packaging is achieved, although the present invention is not limited to this particular application. The tubular actuating mechanisms can be designed to be operated manually, by means of a suitable cord or connecting rod, but they are often provided with electric motors for a convenient motorized reeling and unreeling. The motor driven variant often can be driven manually to allow the actuating of the closure in case of a defect or a power outage. Typically, such tubular actuating mechanisms comprise therefore an electric motor or are adapted to cooperate with such a motor and have a gear reduction assembly, to limit the speed of the electric motor, which is usually much too high for directly reeling or unreeling of the closures. The gear reduction assemblies commonly applied are of the epicyclic gearing type, whereby for most applications three or more stages of such epicyclic gearing is necessary to achieve the desired speed reduction and torque increase.
A typical example of a tubular geared motor for roller blinds is known from the co-owned WO 2010/089243 A2. In this document, a tubular geared motor for roller blinds is disclosed comprising an electric motor and a reduction assembly in form of an epicyclic reduction gear. According to this document, the epicyclic reduction gear has several advantages, namely for example a high reduction ratio, it allows to transmit high torque with at the same time a compact design and a low weight. Further, the output shaft can be subjected to high radial loads. These constructional advantages make such epicyclic reduction gears very useful in roll-type closure applications. However, according to this document, one drawback of such epicyclic gears is that this type of gear tends to amplify the vibrations of the electrical motor and is therefore noisy and transfers vibrations to the surrounding building structure. This drawback is even worsened when several epicyclic reduction gears are arranged in several stages to achieve the desired high reduction ratio. The WO 2010/089243 suggests to reduce these drawbacks by providing an elastic belt between the planet gears and the outer ring gear to damp the occurring vibrations.
From EP 0 976 909 A1 another tubular actuating mechanism for roll-type closures is known, which is again assigned to the same applicant. Also in this document a tubular device is disclosed, comprising an electric motor and several epicyclic reduction gears all arranged in longitudinal direction. This document discloses an improved mechanical irreversibility device, which prevents that the closure to be actuated unreels in uncontrolled way because of its own weight. Instead of the frequently used stop devices in the form of electromagnetic brakes or purely mechanical brakes, the EP 0 976 909 suggests an improved device, which reduces vibrations from the electric motor.
It is an object of the present invention to provide an improved tubular actuating mechanism which offers improved noise and vibration reduction. It is a further object of the present invention to provide such an improved design, which is reliable and compact at the same time, while offering a similar, preferably improved performance over the prior art designs.
These and other objects which will become apparent upon reading the following description are solved by a tubular actuating mechanism for roll-type closures according to claim 1.